Effect of Pre- and Post-Plant Fungicide and Fertilizer Treatments on Infection by Colletotrichum acutatum, Plant Survival, and Yield of Annual Strawberry in Florida

摘要

The effects of pre-plant dips and post-plant treatments on the infection by Colletotrichum acutatum, survival, and yields of strawberry plants were evaluated over two seasons in Florida using naturally infected transplants imported from northern nurseries. Handling practices such as washing, refrigerating, and dipping plants in water had no effect on infection, survival, or yield. Pre-plant dips with the fungicide Switch 62.5 WDG (cyprodinil + fludioxonil) and, in some cases, with Abound 2.08F (azoxystrobin), reduced infection and plant mortality, and increased yield. Pre-plant dips with Oxidate (hydrogen peroxide) were ineffective and, in some cases, increased plant mortality and reduced yield. Fertilizer treatments, such as dipping and spraying plants with Brotomax (8-0-0 plus micronutrients) or application of slow-release Osmocote (15-9-12 plus micronutrients) after planting, had no effect or reduced plant survival and yield. Post-plant application of Surround WP, a kaolin clay intended to reduce heat stress and control mites and insects, had little or no effect on infection, survival, or yield. In summary, strawberry transplants infected with C. acutatum can be dipped in Switch or Abound at planting to reduce infection and increase survival and yield, but other treatments and practices examined are unlikely to have beneficial effects.